Risk of psychological distress in parents of preterm children in the first year: evidence from the UK Millennium Cohort Study

OBJECTIVE: To assess whether the parents of babies born preterm (PT; <37 weeks completed gestation) are at excess risk of psychological distress (PD) at 9 months postpartum, and to explore the influence of the degree of prematurity. DESIGN AND PARTICIPANTS: Data were drawn from the UK Millennium Cohort Study, a nationally representative prospective cohort of babies born in 2000–2002. 12 100 families with complete data available for both parents at recruitment (9 months postpartum) are included. EXPOSURE AND OUTCOME: Mothers report of gestational age at birth (in weeks) was grouped into: very PT (<32 weeks), moderately PT (32–33 weeks), late PT (34–36 weeks), early term (37–38 weeks), full-term (39–41 weeks), post-term (42 weeks). PD was assessed using a modified Rutter Malaise Inventory, a validated instrument that has been used in both men and women to assess levels of anxiety and distress. RESULTS: Overall, 7% of families reported a PT birth; 12.1% of mothers and 8.9% of fathers showed signs of PD at 9 months postpartum. The mothers of very PT infants had an increased risk of PD, compared with the mothers of full-term babies (unadjusted OR 2.10 (1.30 to 3.39; adjusted OR 1.66 (1.02 to 2.69)). Mothers of moderate or late PT babies had no apparent increased risk of PD. However, mothers of early term babies also showed a small excess risk of PD (adjusted OR 1.16 (0.99 to 1.36)). Unadjusted analysis suggested a doubling in the risk of PD in fathers of very and moderately PT babies, compared with fathers of full-term babies, which remains statistically significant after adjustment in the moderately PT group (adjusted OR1.98 (1.20 to 3.29)). CONCLUSIONS: The parents of very PT children are at an increased risk of PD at 9 months postpartum, and mothers of children born at early term also see an elevated risk compared with mothers of full-term babies.